Thin films nonlinear

The microwave properties of oxide based dielectric bulk material, thin film nonlinear dielectric materials and oxide high temperature superconducting materials were reviewed in this article. In addition, the most important microwave measurement techniques have been discussed. Important future directions of related material research aiming towards further integration both on chip and subsystem level, increase of performance and cost reduction are ... 

Chromophoric self-assembled multilayers. Organic superlattice approaches to thin-film nonlinear optical materials, J. Amer. Chem. Soc. 112 7389 (1990). 

Li, D. Ratner, M.A. Marks, T.J. Zhang, C.Yang, J. Wong. G.K. Chromophoric self-assembled multilayers. Organic superlattice approaches to thin-film nonlinear optical materials. J. Am. Chem. Soc. 1990. 112 (20), 7389. 

PPQs possess a stepladder stmcture that combines good thermal stabiUty, electrical insulation, and chemical resistance with good processing characteristics (81). These properties allow unique appHcations in the aerospace and electronics industries (82,83). PPQ can be made conductive by the use of an electrochemical oxidation method (84). The conductivities of these films vary from 10 to 10 S/cm depending on the dopant anions, thus finding appHcations in electronics industry. Similarly, some thermally stable PQs with low dielectric constants have been produced for microelectronic appHcations (85). Thin films of PQs have been used in nonlinear optical appHcations (86,87). 

Some quinones, having the ability to form intra- and/or intermolecular hydrogen bonds, exhibit high molecular hyperpolarizability and are third-order nonlinear optical (NLO) materials. Compound 39 has a %(3) of 5 x 10 11 esu at 1.9 pm, and is a third-order NLO material.23 The optoelectric properties of quinoid compounds correlate with their structures in crystals or on thin films.23... 

Tanahashi I, Manabe Y, Tohda T, Sasaki S, Nakamura A (1996) Optical nonlinearities of Au/Si02 composite thin films prepared by a sputtering method. J Appl Phys 79 1244-1249... 

Linear and nonlinear optical properties of a class of polydiacetylenes that can be grown as large area and controlled thickness thin films have been investigated. This involved an integrated research effort including monomer synthesis, thin film growth and new measurement techniques. 

The nonlinear optical and dielectric properties of polymers find increasing use in devices, such as cladding and coatings for optical fibres, piezoelectric and optical fibre sensors, frequency doublers, and thin films for integrated optics applications. It is therefore important to understand the dielectric, optical and mechanical response of polymeric materials to optimize their usage. The parameters that are important to evaluate these properties of polymers are their dipole moment polarizability a, hyperpolarizabilities 0... 

Second-Order Nonlinear Optics in Chiral Thin Films... 

In the following sections we will first in Section 2 briefly discuss the necessary background to understand optical activity effects in linear and nonlinear optics and to illustrate the similarities and differences between both types. In Section 3 we present a more thorough analysis of nonlinear optical effects in second-harmonic generation, both from a theoretical and an experimental point of view. Section 4 deals with experimental examples that illustrate the usefulness of nonlinear optical activity in the study of chiral thin films and surfaces. Finally, in Section 5 we give an overview of the role of chirality in the field of second-order nonlinear optics and show that chiral molecules can be useful for applications in this field. 

In this section, the experimental techniques described in the previous section are applied to the study of thin Langmuir-Blodgett films of chiral molecules and polymers. We will show in detail how the second-order susceptibility of chiral thin films can be analyzed and discuss the influence of chirality on the nonlinear optical response of these films. 

Nonlinear optical techniques are extremely useful in characterizing the chiral properties of materials, as is pointed out by Verbiest and Persoons in Chapter 9. These authors give an in-depth discussion of this tool, both from an experimental and theoretical point of view, paying special attention to the characterization of chiral surfaces and thin films. In the second part of their contribution they highlight the role chiral materials can play in the field of nonlinear optics and photonics, which opens the way for a variety of applications. 

Hill, R. A. Knoesen, A. Mortazavi, M. A., Corona poling of nonlinear polymer thin films for electro optic modulators, Appl. Phys. Lett. 1994, 65, 1733 1735... 

NONLINEAR VISCOELASTICITY OF THIN FILM AT AIR/WATER INTERFACE... 

After the accomplishment of the above mentioned experiment on the nonlinear viscoelasticity of the DPPE thin film, we have tried to construct a new instrument for the measurement of the dynamic surface tension. We have noticed that, the blades used to change the surface area in the commercial instrument, did not show genuine triangle or sinusoidal trajectory but rather mathematically undefined. With our newly designed instrument, the time change of the surface area can be controlled according to a chosen function with the aid of a micro-computer. 

Figure 18A shows the Fourier spectra thus obtained. The real and imaginary parts correspond to the elastic and viscous components of the DOPC thin film, respectively. We can see that the spectrum is composed not only from the fundamental (coo) but also from the higher (2harmonic components. Such a trend indicates that the DOPC thin film exhibits rather large nonlinearity in the viscoelastic characteristics. 

In other words, higher harmonics serve as a useful quantitative measure of the nonlinear characteristics of the thin film. Using the inverse Fourier... 

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